Steerable needle assembly for use in vertebral body augmentation

Abstract

Disclosed herein are devices for minimally invasive vertebral augmentation and restoration of spinal lordosis using a steerable cannula assembly. When deployed, the articulating cannula, including an outer cannula and an inner cannula extending into a central lumen of the outer cannula and coupled to each other at their distal ends, can be manipulated to curve/bend the body of the articulating cannula. This manipulation is used to create a void within the interior body and may also be used to control delivery of a treatment element to the interior body.

What is claimed is: 
     
       1. A steerable cannula assembly comprising:
 an outer cannula having a central lumen extending therethrough, the outer cannula including an articulating portion that curves in response to a force applied to a proximal end of the outer cannula; 
 an inner cannula having a central lumen extending therethrough, the inner cannula being sized and configured to extend into a portion of the central lumen of the outer cannula, and coupled to a distal end of the outer cannula, wherein a tube-shaped sealing barrier covers at least a portion of an outer surface of the inner cannula; 
 wherein the steering cannula assembly further includes an opening extending through a wall of the outer cannula and a wall of the inner cannula, the opening configured to provide access to the central lumen of the inner cannula. 
 
     
     
       2. The assembly of  claim 1 , wherein the inner cannula is coupled to the outer cannula at the distal end of the outer cannula by at least one of a chemical bond, a thermal bond, and a mechanical bond. 
     
     
       3. The assembly of  claim 1 , wherein the force applied to the proximal end of the outer cannula results in movement of the proximal end in a direction along a longitudinal axis of the outer cannula. 
     
     
       4. The assembly of  claim 1 , wherein the articulating portion includes a plurality of grooves and a plurality of corresponding projections, wherein at least two of the plurality of projections are sized and configured to interlock when the articulating portion is in a fully curved state. 
     
     
       5. The assembly of  claim 1 , wherein the inner cannula includes a slot extending along a longitudinal axis of the inner cannula. 
     
     
       6. The assembly of  claim 5 , wherein the inner cannula includes at least two slots extending along a longitudinal axis of the inner cannula,
 wherein a support member is provided between each of the slots, the support member comprising a ring-shaped portion extending in a direction perpendicular to the longitudinal axis of the inner cannula and having a having a central lumen extending therethrough. 
 
     
     
       7. The assembly of  claim 1 , further including a handle operably coupled to the outer cannula and the inner cannula, the handle including:
 a body portion fixedly engaged to a proximal end of the inner cannula; 
 a ratchet assembly for applying the force to the proximate end of the outer cannula and moving the proximal end in a direction along the longitudinal axis of the outer cannula; and 
 a lever operably coupled to the ratchet assembly. 
 
     
     
       8. The assembly of  claim 7 , further including a first connector coupled to a proximal end of the outer cannula, the first connector having a central lumen extending therethrough, and an outer surface sized and configured to matingly engage a ratchet assembly associated with the handle. 
     
     
       9. The assembly of  claim 8 , wherein the outer surface of the first connector includes a projection sized and configured to engage an interior surface of the handle. 
     
     
       10. The assembly of  claim 7 , further comprising a second connector coupled to a proximal end of the inner cannula, the second connector including a central lumen extending therethrough. 
     
     
       11. The assembly of  claim 10 , wherein the outer surface of the second connector includes a recess and a collar sized and configured to engage a body portion of a handle. 
     
     
       12. A method for treating a body using an steerable cannula assembly, the method comprising:
 inserting an articulating cannula into an interior body, the articulating cannula including an outer cannula and an inner cannula extending into a central lumen of the outer cannula, the outer cannula coupled to the inner cannula at their distal end, wherein a tube-shaped sealing barrier covers at least a portion of an outer surface of the inner cannula, and further wherein the steerable cannula assembly further includes an opening extending through a wall of the outer cannula and a wall of the inner cannula, the opening configured to provide access to the central lumen of the inner cannula; 
 selectively adjusting the articulating cannula to cause a portion of the articulating cannula to curve; 
 augmenting the interior body; and 
 withdrawing the articulating cannula from the interior body. 
 
     
     
       13. The method of  claim 12 , wherein selectively adjusting the articulating cannula includes:
 maintaining a position of a proximal end of the inner cannula with respect to the steerable cannula assembly; and 
 applying a force to the outer cannula in a direction along a longitudinal axis of the outer cannula. 
 
     
     
       14. The method of  claim 12 , wherein selectively adjusting the articulating cannula further includes:
 apply the force to the outer cannula such that a width of a plurality of grooves located on the outer cannula is decreased; and 
 applying the force to the outer cannula such that a plurality of corresponding projections located on the outer cannula interlock when the articulating cannula is in a fully curved position. 
 
     
     
       15. The method of  claim 12 , wherein selectively adjusting the articulating cannula further includes:
 maintaining a position of the proximal end of the inner cannula such that a slot extending along a longitudinal axis of the inner cannula provides a flexation point for the inner cannula. 
 
     
     
       16. The method of  claim 12 , wherein selectively adjusting the articulating cannula further includes:
 coupling a ratchet assembly to the outer cannula such that variable action of the ratchet assembly corresponds to a complimentary force applied to the outer cannula. 
 
     
     
       17. The method of  claim 12 , further comprising:
 providing a treatment element through the articulating cannula and into the interior body, 
 wherein the treatment element comprises at least one of an inflatable body and a filler material, the filler material comprising at least one of a bone cement, bone chips, demineralized bone, or an implant. 
 
     
     
       18. The method of  claim 12 , further comprising:
 selectively adjusting the articulating cannula to create a cavity in the interior body. 
 
     
     
       19. The method of  claim 12 , further comprising:
 inserting the articulating cannula through a pedicle of a vertebrae and into a body of the vertebrae. 
 
     
     
       20. The method according to  claim 12 , wherein the articulating cannula is introduced into the interior body via an introducer cannula, such that a distal end of the articulating cannula extends beyond a distal end of the introducer cannula and into the interior body.